全文获取类型
收费全文 | 3135篇 |
免费 | 108篇 |
国内免费 | 73篇 |
专业分类
化学 | 551篇 |
晶体学 | 24篇 |
力学 | 3篇 |
综合类 | 1篇 |
数学 | 2347篇 |
物理学 | 390篇 |
出版年
2024年 | 2篇 |
2023年 | 14篇 |
2022年 | 29篇 |
2021年 | 29篇 |
2020年 | 36篇 |
2019年 | 91篇 |
2018年 | 92篇 |
2017年 | 51篇 |
2016年 | 29篇 |
2015年 | 38篇 |
2014年 | 109篇 |
2013年 | 228篇 |
2012年 | 55篇 |
2011年 | 204篇 |
2010年 | 163篇 |
2009年 | 215篇 |
2008年 | 256篇 |
2007年 | 247篇 |
2006年 | 173篇 |
2005年 | 142篇 |
2004年 | 133篇 |
2003年 | 106篇 |
2002年 | 95篇 |
2001年 | 58篇 |
2000年 | 84篇 |
1999年 | 109篇 |
1998年 | 92篇 |
1997年 | 50篇 |
1996年 | 71篇 |
1995年 | 73篇 |
1994年 | 66篇 |
1993年 | 49篇 |
1992年 | 38篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 9篇 |
1986年 | 7篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有3316条查询结果,搜索用时 15 毫秒
991.
T. Le Tat 《Journal of Pure and Applied Algebra》2003,177(3):253-285
The postulation of a space curve is a classifying invariant which computes for any integer n the dimension of the family of surfaces of degree n containing the curve. We prove that for any integers d and g satisfying d−3?g?2d−9, there exists a smooth connected curve of degree d and genus g with the minimal postulation expected by the Riemann-Roch theorem. 相似文献
992.
J.F. Jardine 《Journal of Pure and Applied Algebra》2003,177(2):177-201
A separable transfer map is defined for finite surjective morphisms from integral schemes to a Noetherian integral normal base, for both chain complexes of sheaves and presheaves of spectra. The spectrum level transfer is a map from a direct image paired with the classifying space of a translation groupoid, and taking values in the original presheaf. More traditional transfer maps are recovered from global sections of the stack associated to this groupoid. These constructions can be made in a big site model for the motivic stable category. 相似文献
993.
994.
Hui-Sheng Ding Jin Liang Gaston M. N’Guérékata Ti-Jun Xiao 《Nonlinear Analysis: Theory, Methods & Applications》2008
This paper is concerned with neutral nonlinear delay integral equations. We establish an existence theorem for positive almost automorphic solutions to the equations, which extend some existing results even in the case of almost periodicity. Some examples are given to illustrate our results. 相似文献
995.
Let Z be a field of characteristic ≠2, D be a quaternion division algebra over Z and have a nonstandard involution of the first kind. The fundamental theorem of geometry of 2× 2 Hermitian matrices over D are proved. Thus, if D is a quaternion division algebra over Z with an involution of the first kind, then the fundamental theorem of geometry of 2× 2 Hermitian matrices over D are obtained. 相似文献
996.
Rüdiger Plantiko 《manuscripta mathematica》1995,87(1):527-543
If π:X→B is a non-Kählerian elliptic surface with generic fibreF, the moduli space of stable holomorphic vector bundles with torsion Chern classes onX has an induced fibred structure with base Pico(F) and the moduli space of stable parabolic bundles onB orb as fibre. This is specific to the non-Kähler case. 相似文献
997.
We show that the Hilbert functor of rank one families on a non-separated scheme X admits deformations that are not effective. For such ambient schemes we have that the Hilbert functor is not representable
by a scheme or an algebraic space. 相似文献
998.
In this paper we study the persistence of lower dimensional hyperbolic invariant tori for nearly integrable twist symplectic mappings. Under a Rüssmann-type non-degenerate condition, by introducing a modified KAM iteration scheme, we proved that nearly integrable twist symplectic mappings admit a family of lower dimensional hyperbolic invariant tori as long as the symplectic perturbation is small enough. 相似文献
999.
We study Brauer-Manin obstructions to the Hasse principle and to weak approximation, with special regard to effectivity questions. 相似文献
1000.
We prove that the invariant Hilbert scheme parameterising the equivariant deformations of the affine multicone over a flag variety is, under certain hypotheses, an affine space. More specifically, we obtain that the isomorphism classes of equivariant deformations of such a multicone are in correspondence with the orbits of a well-determined wonderful variety. 相似文献